Scaffold frame section with integral guard rail post

ABSTRACT

An enhanced safety scaffold assembly ( 10 ) is provided including end frames ( 12,14 ) interconnected by means of cross-tie structure ( 18,20 ). The end frames ( 12,14 ) include ledgers ( 36 ) located a safety distance ( 38 ) of at least about thirty inches below the upper ends ( 26   b,   28   b ) of the standards ( 26,28 ), and are free of additional ledgers within the safety distance. A platform ( 16 ) is supported by the ledgers ( 36 ), and guardrail assemblies ( 22,24 ) extend between opposed standards ( 26,28 ). In this way, the platform ( 16 ) is located well below the upper ends ( 26   b,   28   b ) of the standards ( 26,28 ) in accordance with existing safety regulations, and placement of a platform ( 16 ) in an unsafe, elevated position is precluded. The assemblies of the invention may be constructed in a variety of ways to include optional leveling units ( 58 ), ladders ( 44 ), outriggers ( 134 ) and supplemental work platforms ( 144 ).

CROSS REFERENCE TO RELATED APPLICATION

This application is being filed contemporaneously with application forU.S. Design patent Ser. No. ______, entitled SCAFFOLD FRAME SECTION WITHINTEGRAL GUARD RAIL POST, which is hereby incorporated by referenceherein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is broadly concerned with improved scaffoldassemblies and components thereof which are designed for enhanced usersafety. More particularly, the invention is concerned with scaffoldassemblies and the end frames forming a part thereof, wherein personnelplatform-supporting ledgers are provided at a significant safetydistance below the upper ends of the platform end frames so that a useris precluded from positioning a personnel platform at an elevated,unsafe position.

2. Description of the Prior Art

Scaffolding of various types has been provided in myriad forms over theyears. To be effective, construction site scaffolding must be relativelyeasy to assemble and provide a degree of flexibility so that scaffoldingof various heights and widths can be built. At the same time, suchscaffolding must be sturdy and structurally sound when constructed.

In recent years, safety regulations have mandated that personnelplatforms forming a part of scaffolding be located below the upper endsof the scaffolding, so that appropriate guardrails can be installed andare effective. As can be appreciated, if a personnel platform is locatednear the very top of a scaffolding unit, workers standing on theplatforms may be subjected to significant falling hazard owing to thefact that inadequate guardrails are present.

While these safety standards have been in place for several years, it isstill possible with existing scaffold designs to inadvertently orintentionally construct a scaffold assembly with improperly and unsafelypositioned personnel platforms. This is because of the fact that priorscaffold frames have cross bars (often referred to as “ledgers”) closeto or adjacent the upper end of the scaffold standards. In such a case,those constructing the scaffolding, either from expediency or lack ofunderstanding of the safety rules, can place the platforms in unsafeelevated positions. Furthermore, during assembly of conventionalscaffolding, workers are often required to stand on unguarded platformswhile the next (upper) frame section and other scaffolding componentsare attached to the frame upon which the worker is supported.

There is accordingly a need in the art for improved scaffolding whichmakes it essentially impossible to place personnel platforms inelevated, unsafe positions in violation of existing safety standards.

SUMMARY OF THE INVENTION

The present invention overcomes the problems outlined above, andprovides a scaffold assembly including a pair of end frames, eachcomprising a pair of laterally spaced apart, upright standards havingopposed upper and lower ends, with a primary platform ledger extendingbetween and interconnected with the standards. Each primary ledger islocated a safety distance of at least about thirty (30) inches (morepreferably from about thirty-six (36) to forty-two (42) inches) belowthe upper end of the corresponding standard. One or more personnelplatforms span and are operatively supported by the end frame ledgers.Additionally, the end frames are free of platform ledgers within thesafety distance above the primary ledger, so that no platform may beinstalled above the primary ledgers. In order to erect a free-standingscaffold, cross-tie structure is employed to interconnect the endframes. Finally, the overall scaffold assembly has a guardrail assemblyextending between the end frames in the safety distance above thepersonnel platform.

The scaffold assemblies of the invention may be provided in stackedrelationship, i.e., two or more such assemblies may be placed one atopthe other and interconnected. To this end, the scaffolds are designedfor such vertical interconnection by means of connection insert pins atthe upper ends of the corner standards, which telescope into the tubularends of the standards of the scaffold assembly next above.

In addition, the scaffold assemblies of the invention may be providedwith auxiliary features such as leveling units, end ladders, outriggers,supplemental work platforms and quick-connectors.

Another aspect of the present invention concerns scaffold end frameincluding a pair of laterally spaced apart, upright standards havingopposed upper and lower ends. The end frame further includes a primaryplatform ledger extending between and being interconnected with thestandards. The primary ledger is capable of supporting the end of apersonnel platform. Moreover, the primary platform ledger is located asafety distance of at least about thirty (30) inches below each of thestandard upper ends. The end frame is free of platform ledgers withinthe safety distance above the primary ledger.

Other aspects and advantages of the present invention will be apparentfrom the following detailed description of the preferred embodiments andthe accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

A preferred embodiment of the present invention is described in detailbelow with reference to the attached drawing Figures, wherein:

FIG. 1 is a perspective view of a scaffold assembly in accordance withthe invention;

FIG. 2 is a side elevational view of the scaffold assembly depicted inFIG. 1, shown during erection of another scaffold section atop the basescaffold assembly;

FIG. 3 is a perspective view of a scaffold assembly in accordance withthe invention, made up of two interconnected sections;

FIG. 4 is a side elevational view of a scaffold end frame in accordancewith the invention;

FIG. 5 is a perspective view of another scaffold assembly in accordancewith the invention, with the work scaffold assembly positioned atop alow-rise scaffold base;

FIG. 6 is a perspective view of another type of scaffold end frame;

FIG. 7 is a perspective view similar to that of FIG. 6 but showinganother type of scaffold end frame; and

FIG. 8 is a perspective view of a multiple-tier scaffold assembly inaccordance with the invention, equipped with ground-engaging outriggersand an uppermost outrigger work platform.

The drawing figures do not limit the present invention to the specificembodiments disclosed and described herein. The drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to the drawings, the scaffold assembly 10 selected forillustration in FIG. 1 broadly includes a pair of preconstructed endframes 12,14, a personnel platform 16, cross-tie assemblies 18,20, andguardrail assemblies 22,24. As shown, the assembly 10 is a free-standingunit for use on construction sites or in similar contexts.

In more detail, the end frames 12,14 in the depicted embodiment aremirror images of each other. Thus, only the end frame 12 will bedescribed in detail, with the understanding that the other end frame 14is similarly constructed. Furthermore, the same reference numerals willbe used to identify similar components of the end frame 12 and 14.

As perhaps best shown in FIG. 4, the end frame 12 preferably includes apair of upright standards 26,28, each having lower ends 26 a,28 a andupper ends 26 b,28 b. In the preferred embodiment, the standards areformed of metal (e.g., steel or Aluminum) and have a circular, tubularconfiguration, although other suitable materials and configurations arewithin the ambit of the present invention. The standards 26,28 arepreferably provided with a series of equally spaced apart accessoryattachment holes 30 along the length thereof. As will be described, theattachment holes 30 removably receive connection pins so as to permitattachment of any variety of scaffolding accessories to the standard.Each standard is also preferably provided with three spaced apartinwardly projecting pin-type locks 32,33,34. The overall end frame 12also has a primary ledger 36 which extends between and is connected tothe standards 26,28. Preferably, the ledger 36 is formed of the samematerial as the standards 26,28 and similarly presents a circulartubular cross-section. The preferred ledger 36 is integrally connectedto the standards 26,28 by suitable means, such as welding.

Moreover, the ledger 36 is located a safety distance 38 below the upperends 26 b,28 b of the ledgers. This safety distance 38 is at least aboutthirty (30) inches, and more preferably is from about thirty-six (36) toforty-two (42) inches. The ledger 36 is additionally supported by anend-mounted angular brace 40 secured to the underside of the ledger 36and to the adjacent standard 26 at a point beneath the ledger. Similarto the standards 26,28 and ledger 36, the brace 40 is preferably formedof cylindrical, tubular, metal bar. However, if desired, the ledger mayalternatively be constructed in a manner similar to that disclosed incopending U.S. patent application Ser. No. 10/950,113, filed Sep. 24,2004, entitled WALKBOARD LEDGER FOR SCAFFOLDING, published asPublication No. US 2005/0034922 A1, which is hereby incorporated byreference herein.

The end frame 12 preferably also includes a ladder 44. The ladder 44includes first and second ladder side frames 46,48 as well as lateralrungs 50. As illustrated, the lower ladder side frame 48 is secured tothe underside of ledger 36 and extends downwardly therefrom, with therungs 50 connected between the side frame 48 and standard 28. The upperladder side frame 46 is cantilever mounted through the medium of rungs50 as shown, but does not extend to ledger 36. Those ordinarily skilledin the art will appreciate that this configuration of the upper ladderside frame 46 permits the platform 16 to be positioned on the ledgers 36within the confines of the ladder 44. Although both end frames 12 and 14have been shown as being provided with the ladder 44, in many instancesonly one of the end frames is provided with a ladder 44 to providevertical access to the elevated platform(s) 16. It will also beappreciated that an angular brace is preferably not provided adjacentthe standard 28, as the ladder 44 sufficiently interconnects the ledger36 and standard 28 to provide the desired structural reinforcementtherebetween.

In order to permit erection of a multiple-tier scaffold assembly, eachof the standards 26,28 receives a reduced diameter insert pin stubsection 52,54 extending above the associated upper ends 26 b,28 b. Theand upper ladder side frame 46 also has a reduced diameter stub 56. Thestacked frames may be otherwise secured to one another if desired.

Returning to FIG. 1, it will be seen that each of the end framesincludes a pair of screw-type leveling units 58, each being associatedwith a respective one of the standards 26,28. The units 58 areconventional and can be used to individually level each of the standardsas required.

The platform (also known as a walkboard) 16 preferably includeselongated side rails 60 as well as interconnected transverse end rails62. The rails 60,62 support a substantially flat walkway or platformpanel 64 to support users of the scaffold assembly. The opposed ends ofthe platform 16 are provided with a pair of spaced attachment hooks 66configured to receive the ledger 36 and thus support the platform inuse. As noted previously, the lower end of the upper ladder side frames46 are spaced slightly above the ledger 36; this permits lateralshifting of the platform 16 along the lengths of the ledgers 36 asnecessary. The platform 16 is preferably constructed in a manner similarto that disclosed in U.S. Pat. No. 6,223,857, issued May 1, 2001,entitled SCAFFOLDING PLATFORM, which is hereby incorporated by referenceherein. However, other suitable walkboard designs are within the ambitof the present invention.

The cross-tie assemblies 18,20 each comprise a pair of crossed,angularly oriented tie bars 68,70 which are secured to the opposedstandards 26,28 of the end frames 12,14. As illustrated, each of the tiebars 68,70 has endmost apertured connectors 68 a,70 a which are designedto receive the pin-type locks 33,34 of the standards. The assemblies18,20, thus operatively interconnect the end frames 12,14 so as topresent a free-standing scaffold. The locks 33,34 are conventional indesign and serve to releasably lock the bars 68,70 to the standards26,28 so as to prevent inadvertent removal after assembly.

Finally, the scaffold assembly 10 includes the guardrail assemblies22,24 each comprising a pair of vertically spaced apart guardrail ties72,74 having apertured connection ends 72 a,74 a. These guardrail tiesare attached to the upper pin-type locks 32,33 on the opposed standards26,28. The guard rails 22,24 provide safety to the scaffold user bylaterally constraining any workers on the platform 16. The crossbar ties68,70 and guardrail ties 72,74 are preferably tubular cylindrical metalbars.

An important feature of the end frames 12,14, and thus of the completescaffold assembly 10, is the provision of ledger 36 located at thesafety distance below the upper ends 26 b,28 b of the standards.Moreover, there is no ledger within the safety distance, or closer tothe upper ends of the standards (it will be appreciated thatlow-strength reinforcements could be provided within the safetydistance, but these would not be capable of supporting a platform 16).As such, the users of scaffold assembly 10 are necessarily provided withlengths of standard above the platform 16 which permit installation ofsafety guardrails, and it is impossible for such users to inadvertentlyposition a platform 16 within the safety distance. Furthermore, as shownin FIG. 2, during assembly of the scaffolding 10, the user stands safelyon the platform 16 as he/she stacks end frames one on top of another,all the while being safeguarded by the guardrails.

FIG. 6 illustrates another side frame 76 in accordance with theinvention, which is identical with the side frame 12 of FIG. 4, save forthe fact that the ladder 44 is eliminated and an angular brace 42 isprovided between the ledger 36 and standard 28. Therefore, no extendeddiscussion of this end frame 76 is needed, and the same referencenumerals used in the description of the frame 12 are employed.

A still further end frame 78 is illustrated in FIG. 7. This end frame isidentical with the end frame 76 of FIG. 6, except for the provision of amodified ledger. Specifically, the end frame 78 has a ledger 36associated with longer reinforcing struts 40 a,42 a which extend topoints below that of the corresponding struts 40,42. In addition, theledger 36 is defined by double transoms or bars 80 that are spacedvertically apart. Short connection plates 82 extend between the ledgerbars 80, as shown. Here again, it will be seen that the safety distance38 between upper ledger 80 and the upper ends 26 b,28 b of the standardsis maintained. In use, the platform 16 may be affixed to either of theledger bars 80, but in either case the important safety distance 38remains effective.

The scaffold assemblies of the invention can be constructed in a varietyof ways to meet the needs of a construction site. For example (see FIG.3), two (or more) scaffold assemblies 10,10 a can be positioned one atopthe other to create an overall scaffold of increased height. In FIG. 3,a lower assembly 10 is identical with that described previously, and theupper assembly 10 a is supported on the assembly 10. This involvessecuring the lower ends 26 a,28 a of the upper standards to the insertpins 52,54 of the lower standards. As illustrated in FIG. 2, an upperend frame 14 a is positioned on end frame 14 by telescoping the insertpins 52,54 thereof into the lower tubular ends of the upper standards.When both of the upper end frames 12 a, 14 a are so positioned,cross-tie assemblies and guardrail assemblies are interconnected betweenthe upper standards to complete the construction. FIG. 3 alsoillustrates another feature of the invention, namely that the ledgers 36are sufficient length to accommodate a pair of side-by-side platforms 16as required.

FIG. 5 shows another scaffold assembly 84 made up of a scaffold assembly10 positioned atop a low-rise height extender section 86. The latter issimilar to the scaffold assembly 10, but is not designed to support aplatform and is used simply to create a higher overall scaffold. To thisend, the section 86 includes a pair of pre-fabricated end frames 88,90,each having upright standards 92,94 as well as uppermost cross brace 96.The end frames 88,90 are interconnected by a cross-tie assemblies 98 asillustrated.

Finally, FIG. 8 depicts a two-tier scaffold assembly 100 made up of twostacked scaffold assemblies 102,104. The assembly 102,104 is made up ofend frames 106,108 including upright standards 110,112 and ledgers 114extending between and interconnecting the standards. The ledgers 114 arelocated the safety distance 38 from the upper ends of the associatedstandards, and support a pair of platforms 116. A cross-tie structure118,120 is used to interconnect the end frames 106,108, whereasguardrail assemblies 122,124 are secured to the standards within thesafety distance. In this case, however, the end frames 106,108 havesecondary guardrail assemblies 126 which augment the assemblies 122,124.Each of the end guardrail assemblies 126 is in the form of a pair ofvertically spaced apart, laterally extending rails 128,130 withinterconnecting angular struts 132. The end guardrail assemblies 126 areeach conveniently attached to the standards 110,112 by connection pins,each of which is received in an opening defined in the assembly 126 andan aligned attachment hole 133 of the standard 110 or 112.

The lower assembly 102 is further supported by provision of fouroutriggers 134 respectively secured to each of the end frame standards.Each outrigger 134 includes an outboard vertical leg 136 together withhorizontal and angular connection struts 138,140 secured to leg 136 andclamped to the associated end frame standard via clamps 142.

The upper scaffold assembly 104 is substantially identical with assembly102 and thus need not be described in detail. However, it will beobserved that the 104 assembly has, in lieu of the guardrail assembly122, a secondary platform assembly 144. The assembly 144 includes apersonnel platform 146 as well as upwardly extending, endmost standards148,150 which support vertically spaced apart guardrail tie rods152,154. The assembly 144 is secured to upper scaffold assembly 104 bymeans of depending angular struts 156 attached to the standards 110 viaconnection pins 158 (again, each being received in an opening in thestrut 156 and an aligned one of the attachment holes 133). Thoseordinarily skilled in the art will appreciate that the scaffolding isparticularly useful in permitting various scaffolding accessories (e.g.,the secondary guardrail assemblies 126, the secondary platform assembly144, pulley-type winches, etc.) to be simply and quickly attached to thestandards. That is, the equally spaced apart attachment holes provide asystem by which auxiliary scaffold components can be universallydesigned for uncomplicated association with the end frames.

The preferred forms of the invention described above are to be used asillustration only, and should not be utilized in a limiting sense ininterpreting the scope of the present invention. Obvious modificationsto the exemplary embodiments, as hereinabove set forth, could be readilymade by those skilled in the art without departing from the spirit ofthe present invention.

The inventor hereby states his intent to rely on the Doctrine ofEquivalents to determine and assess the reasonably fair scope of thepresent invention as pertains to any apparatus not materially departingfrom but outside the literal scope of the invention as set forth in thefollowing claims.

Having thus described the preferred embodiments of the invention, whatis claimed as new and desired to be protected by Letters Patent includesthe following:

1. A scaffold assembly, comprising: a pair of end frames, each comprising a pair of laterally spaced apart, upright standards having opposed upper and lower ends, with a primary platform ledger extending between and interconnected with said standards, said primary platform ledger being located a safety distance of at least about thirty inches below each of said standard upper ends, said end frames being free of platform ledgers within said safety distance above said primary ledger; a personnel platform extending between said end frames and supported by said ledgers of the end frames; cross-tie structure interconnecting said end frames to present a free-standing scaffold assembly; and a guardrail assembly extending between said end frames in said safety distance above said personnel platform.
 2. The scaffold assembly as claimed in claim 1, said platform having a pair of hooks adjacent each end thereof, said hooks engaging the adjacent ledger.
 3. The scaffold assembly as claimed in claim 2, said platform being laterally shiftable along the lengths of said ledgers.
 4. The scaffold assembly as claimed in claim 3, at least one of said end frames having a ladder unit.
 5. The scaffold assembly as claimed in claim 1, said safety distance being from about thirty-six to forty-two inches below the upper ends of said standards.
 6. The scaffold assembly as claimed in claim 1, said cross-tie structure comprising a pair of crossing, angularly oriented tie bars operatively connected to opposed standards of said end frames.
 7. The scaffold assembly as claimed in claim 1, said guardrail assembly comprising at least one guardrail cross-tie extending between opposed standards of said end frames and substantially perpendicular thereto.
 8. The scaffold assembly as claimed in claim 1, each of said end frames including a pair of leveling units, each being affixed to a respective one of the lower ends of the standards.
 9. The scaffold assembly as claimed in claim 1, said ledgers being integrally attached to said standards.
 10. The scaffold assembly as claimed in claim 1, each of said standards including a pin-type lock for attachment of said cross-tie structure thereto.
 11. The scaffold assembly as claimed in claim 1; and a plurality of personnel platforms located in side-by-side relationship and each supported by said end frame ledgers.
 12. The scaffold assembly as claimed in claim 1, each of said end frames including at least one angularly disposed reinforcement brace extending between an underside of said ledger and a point on a corresponding one of the standards below the ledger.
 13. The scaffold assembly as claimed in claim 1, said primary ledger comprising a pair of closely spaced apart, laterally extending ledger bars, said ledger bars both being spaced said safety distance below each of said standard upper ends.
 14. The scaffold assembly as claimed in claim 1, said upper ends of the standards being tubular, each of said end frames including a pair of reduced diameter insert pins, each of which is removably received in a respective one of the upper ends of the standards and projecting upwardly therefrom so as to permit attachment of another end frame atop of the end frame.
 15. The scaffold assembly as claimed in claim 14; and another of said scaffold assemblies located atop said first-mentioned scaffold assembly and secured to and supported thereby, said insert pins being received within the lower ends of the standards of said another of said scaffold assemblies.
 16. The scaffold assembly as claimed in claim 1; and an outrigger assembly operatively coupled to and extending from each of said standards.
 17. The scaffold assembly as claimed in claim 1; a secondary personnel platform assembly secured to opposed standards of said end frames and including a secondary personnel platform, with said secondary platform being located at said safety distance below the upper ends of said standards, a secondary personnel platform assembly further including a secondary guardrail assembly extending upwardly from the secondary platform.
 18. The scaffold assembly as claimed in claim 1, each of standards being provided with a plurality of accessory attachment holes spaced equidistantly along the length thereof; and a scaffolding accessory having at least a pair of attachment openings spaced apart a distance equal to that defined between corresponding attachment holes, each of said end frames including a plurality of connection pins, each being received in aligned ones of the attachment holes and openings to removably attach the accessory to the corresponding standard.
 19. The scaffold assembly as claimed in claim 18, said scaffold accessory comprising a secondary personnel platform assembly secured to opposed standards of said end frames and including a secondary personnel platform, with said secondary platform being located at said safety distance below the upper ends of said standards.
 20. A scaffold end frame comprising: a pair of laterally spaced apart, upright standards having opposed upper and lower ends; and a primary platform ledger extending between and being interconnected with said standards, said primary ledger being capable of supporting the end of a personnel platform, said primary platform ledger located a safety distance of at least about thirty inches below each of said standard upper ends, said end frame being free of platform ledgers within said safety distance above said primary ledger.
 21. The scaffold end frame as claimed in claim 20; and a ladder unit extending generally vertically alongside one of the standards.
 22. The scaffold end frame as claimed in claim 20, said safety distance being from about thirty-six to forty-two inches below the upper ends of said standards.
 23. The scaffold end frame as claimed in claim 20; and a pair of leveling units, each being affixed to a respective one of the lower ends of the standards.
 24. The scaffold end frame as claimed in claim 20, said upper ends of the standards being tubular; and a pair of reduced diameter insert pins, each of which is removably received in a respective one of the upper ends of the standards and projecting upwardly therefrom so as to permit attachment of another end frame atop said end frame.
 25. The scaffold end frame as claimed in claim 20, each of said standards including a pin-type lock secured thereto.
 26. The scaffold end frame as claimed in claim 20; and at least one angularly disposed reinforcement brace extending between an underside of said ledger and a point on a corresponding one of the standards below the ledger.
 27. The scaffold end frame as claimed in claim 20, said primary ledger comprising a pair of closely spaced apart, laterally extending ledger bars, said ledger bars both being spaced said safety distance below each of said standard upper ends.
 28. The scaffold end frame as claimed in claim 20, said primary ledger being the sole ledger extending between said standards.
 29. The scaffold end frame as claimed in claim 20, each of standards being provided with a plurality of accessory attachment holes spaced equidistantly along the length thereof; and a plurality of connection pins, each being received in aligned ones of the attachment holes to permit removable attachment of a scaffolding accessory to the corresponding standard. 